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  <title>Gets the number of fields in the result set</title>
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    <li>Gets the number of fields in the result set</li>
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<div id="layout">
  <div id="layout-content"><div id="mysqli-result.field-count" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">mysqli_result::$field_count</h1>
  <h1 class="refname">mysqli_num_fields</h1>
  <p class="verinfo">(PHP 5, PHP 7, PHP 8)</p><p class="refpurpose"><span class="refname">mysqli_result::$field_count</span> -- <span class="refname">mysqli_num_fields</span> &mdash; <span class="dc-title">Gets the number of fields in the result set</span></p>

 </div>

 <div class="refsect1 description" id="refsect1-mysqli-result.field-count-description">
  <h3 class="title">说明</h3>
  <p class="para">面向对象风格</p>
  <div class="fieldsynopsis"><span class="type">int</span> <var class="varname"><a href="mysqli-result.field-count.html">$mysqli_result-&gt;field_count</a></var>;</div>

  <p class="para">过程化风格</p>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>mysqli_num_fields</strong></span>(<span class="methodparam"><span class="type"><a href="class.mysqli-result.html" class="type mysqli_result">mysqli_result</a></span> <code class="parameter">$result</code></span>): <span class="type">int</span></div>

  <p class="para rdfs-comment">
   Returns the number of fields in the result set.
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-mysqli-result.field-count-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>
    <dt>

<code class="parameter">result</code></dt>
<dd>
<p class="para">仅以过程化样式：由
<span class="function"><a href="mysqli.query.html" class="function">mysqli_query()</a></span>、<span class="function"><a href="mysqli.store-result.html" class="function">mysqli_store_result()</a></span>、
<span class="function"><a href="mysqli.use-result.html" class="function">mysqli_use_result()</a></span>、<span class="function"><a href="mysqli-stmt.get-result.html" class="function">mysqli_stmt_get_result()</a></span> 返回的 <span class="classname"><a href="class.mysqli-result.html" class="classname">mysqli_result</a></span> 对象。</p></dd>

   </dl>

  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-mysqli-result.field-count-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   An <span class="type">int</span> representing the number of fields.
  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-mysqli-result.field-count-examples">
  <h3 class="title">范例</h3>
  <div class="example" id="example-1533">
   <p><strong>示例 #1 面向对象风格</strong></p>
   <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /><br />mysqli_report</span><span style="color: #007700">(</span><span style="color: #0000BB">MYSQLI_REPORT_ERROR&nbsp;</span><span style="color: #007700">|&nbsp;</span><span style="color: #0000BB">MYSQLI_REPORT_STRICT</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$mysqli&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">mysqli</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_user"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_password"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"world"</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #DD0000">"SELECT&nbsp;Name,&nbsp;CountryCode,&nbsp;District,&nbsp;Population&nbsp;FROM&nbsp;City&nbsp;ORDER&nbsp;BY&nbsp;ID&nbsp;LIMIT&nbsp;1"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;Get&nbsp;the&nbsp;number&nbsp;of&nbsp;fields&nbsp;in&nbsp;the&nbsp;result&nbsp;set&nbsp;*/<br /></span><span style="color: #0000BB">$field_cnt&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">$result</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">field_count</span><span style="color: #007700">;<br /><br /></span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Result&nbsp;set&nbsp;has&nbsp;%d&nbsp;fields.\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$field_cnt</span><span style="color: #007700">);</span>
</span>
</code></div>
   </div>

  </div>
  <div class="example" id="example-1534">
   <p><strong>示例 #2 过程化风格</strong></p>
   <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /><br />mysqli_report</span><span style="color: #007700">(</span><span style="color: #0000BB">MYSQLI_REPORT_ERROR&nbsp;</span><span style="color: #007700">|&nbsp;</span><span style="color: #0000BB">MYSQLI_REPORT_STRICT</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$link&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">mysqli_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_user"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_password"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"world"</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">mysqli_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"SELECT&nbsp;Name,&nbsp;CountryCode,&nbsp;District,&nbsp;Population&nbsp;FROM&nbsp;City&nbsp;ORDER&nbsp;BY&nbsp;ID&nbsp;LIMIT&nbsp;1"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;Get&nbsp;the&nbsp;number&nbsp;of&nbsp;fields&nbsp;in&nbsp;the&nbsp;result&nbsp;set&nbsp;*/<br /></span><span style="color: #0000BB">$field_cnt&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">mysqli_num_fields</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Result&nbsp;set&nbsp;has&nbsp;%d&nbsp;fields.\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$field_cnt</span><span style="color: #007700">);</span>
</span>
</code></div>
   </div>

   <div class="example-contents"><p>以上例程会输出：</p></div>
   <div class="example-contents screen">
<div class="cdata"><pre>
Result set has 4 fields.
</pre></div>
   </div>
  </div>
 </div>


 <div class="refsect1 seealso" id="refsect1-mysqli-result.field-count-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="mysqli-result.fetch-field.html" class="function" rel="rdfs-seeAlso">mysqli_fetch_field()</a> - Returns the next field in the result set</span></li>
   </ul>
  </p>
 </div>


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